1. Field of the Invention
The present invention relates to a method for producing an electron beam apparatus and an electron beam apparatus, in which a cathode substrate provided with plural electron-emitting devices and an anode substrate for receiving electron beams from the electron-emitting devices of the cathode substrate are mutually opposed across a reduced-pressure space (vacuum environment).
2. Related Background Art
Recently, developments are being made for an application of an electron-emitting device such as a surface conduction electron-emitting device, a field emission electron-emitting device (FE electron-emitting device), or a metal/insulator/metal electron-emitting device (MIM electron-emitting device) to an electron beam apparatus for example a display panel, an image display apparatus utilizing the same, an image forming apparatus such as an image recording apparatus, or a charged beam source.
An electron beam apparatus is constituted of a cathode substrate provided with plural electron-emitting devices and an anode substrate for receiving electron beams from the electron-emitting devices of the cathode substrate are mutually opposed across a reduced-pressure space, and a high voltage of several hundred volts or more (high electric field of 1 kV/mm or higher) is applied between the cathode substrate and the anode substrate, in order to accelerate the electrons from the electron-emitting device. In such environment, if an extraneous substance is present in the vacuum container, such extraneous substance also becomes an unnecessary emission part (electron-emitting portion) other than the proper electron-emitting devices for image display and causes an electron emission.
In case the electron beam apparatus is for example a display panel of an image display apparatus, such unnecessary emission part constitutes a continuously light emitting source of DC type by the application of the high voltage, thus generates a very bright point even with a very slight current (for example 1 nA or less), and becomes a very annoying obstacle. Such unnecessary emission part is assumed to be caused by formation of a projection, an MIM structure or an MIV (metal/insulator/vacuum) structure by the contamination with the extraneous substance. The electron emission or light emission caused by such unnecessary emission part is generally called an electron group unnecessary for imaging, a floating electron group, a stray electron emission or an abnormal light emission, but will be called stray emission (also abbreviated as SE) in the present specification.
In the producing process for an electron beam apparatus, particularly an image forming apparatus utilizing surface conduction electron-emitting devices, it is proposed to oppose an electrode of an anode substrate to a wiring of a cathode substrate, and to apply a certain high voltage between the wiring and the electrode (such operation generally called a conditioning) to generate a discharge phenomenon, thereby eliminating an unnecessary emission part (SE source) (for example cf. WO00/044022).
However, such prior method, requiring a conditioning on the entire apparatus, is associated with a drawback of causing an accidental discharge in a portion not showing SE, thereby causing a deterioration of the components. Also the conditioning operation, because of an excessively high voltage applied to the entire panel, causes an increased danger for a discharge and, though intended for eliminating the SE source, results in a damage by an accidental discharge, thereby leading to a deterioration in the image. Also, for example in an image display apparatus, a discharge threshold voltage of the SE source is often far higher (2 to 10 times) than the voltage applied at the image display, and it is difficult to apply such high voltage over the entire panel.